In an air-conditioning apparatus configured by connecting a plurality of second units to at least one or more first units by pipes, connection information indicating the relation of connection between the second units and the branched pipes is usually set manually by workers upon the construction work on the installation location of the apparatus. Since the connection of pipes for the second units and the setting of connection information are independently performed, construction errors may occur in which the correspondence relation between a pipe to which the second unit is connected (connected pipe) and a pipe set as connection information (setting pipe) do not agree to one another (there is an incorrect correspondence relation).
Where there is an incorrect correspondence relation, it is not possible to normally perform indoor temperature conditioning in any of the second units, and customer complaints may occur after the product is delivered to the user.
Therefore, technologies have conventionally been developed that automatically detect disagreements in the correspondence relations between the connected pipes and the setting pipes (see, for example, Patent Literatures 1 and 2).
In the air-conditioning apparatus described in Patent Literature 1, it is determined that the indoor heat exchanger is functioning as a condenser where the refrigerant temperature within the indoor heat exchanger of an indoor unit is higher than the suction air temperature, and it is determined that the indoor heat exchanger is functioning as an evaporator where the refrigerant temperature is lower than the suction air temperature. The apparatus is configured such that, where the indoor unit is switched to a cooling or a heating operation, it is determined in the indoor unit whether its connection with the corresponding branching valve unit via a signal line is appropriate by determining which of a condenser and an evaporator the indoor heat exchanger of the indoor unit is functioning as.
Further, the air-conditioning apparatus disclosed in Patent Literature 2 is such that in a splitting unit in which refrigerant splitting is adjusted of an indoor unit, by repeating multiple times an operation in which a substantially half of a solenoid valve being open in the splitting unit is closed on the test run, and a substantially half of a solenoid valve having been closed is opened, to thereby accurately detect correspondence relations between the indoor unit and the solenoid valve within the splitting unit in a short time so that it is possible to accurately perform cooling and heating operations of a desired indoor unit.